Orthogonal Frequency-Division Multiple Access Distributed Channel Access

ABSTRACT

This disclosure describes methods, apparatus, and systems related to an OFDMA Distributed Channel Access. A first computing device comprising one or more processors and one or more transceiver components may determine one or more random access resource allocations. The first computing device may generate a trigger frame associated with the one or more random access resource allocations. The first computing device may cause to send the trigger frame to one or more user devices including a first user device. The first computing device may receive from the first user device, in response to sending the trigger frame, a first uplink frame based on a first backoff count associated with the first user device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/111,533, filed Feb. 3, 2015 the disclosure of which is incorporatedherein by reference.

TECHNICAL FIELD

This disclosure generally relates to systems and methods for wirelesscommunications and, more particularly, to scheduling medium access.

BACKGROUND

Wireless devices are becoming widely prevalent and are increasinglyrequesting access to wireless channels. A next generationHigh-Efficiency Wi-Fi (HEW) standard is under development. HEW userdevices rely on resource allocations by one or more access points tofacilitate data transmissions on a communication channel. One HEW userdevice may select a resource that may coincide with another HEW userdevice resource selection.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a network diagram illustrating an example networkenvironment of an illustrative orthogonal frequency-division multipleaccess (OFDMA) distributed channel access system (ODCA), according toone or more example embodiments of the disclosure;

FIG. 2 depicts an illustrative schematic diagram between components ofan illustrative ODCA system in accordance with one or more exampleembodiments of the present disclosure;

FIG. 3 depicts an illustrative schematic diagram between components ofan illustrative ODCA system in accordance with one or more embodimentsof the disclosure;

FIG. 4 depicts a flow diagram of an illustrative process for anillustrative ODCA system in accordance with one or more embodiments ofthe disclosure;

FIG. 5 depicts a flow diagram of an illustrative process for anillustrative ODCA Access system in accordance with one or moreembodiments of the disclosure;

FIG. 6 illustrates a functional diagram of an example user device orexample access point according to one or more example embodiments of thedisclosure; and

FIG. 7 shows a block diagram of an example of a machine upon which anyof one or more techniques (e.g., methods) may be performed according toone or more embodiments of the disclosure discussed herein.

DETAILED DESCRIPTION

Example embodiments described herein provide certain systems, methods,and devices for providing signaling information to Wi-Fi devices invarious Wi-Fi networks, including, but not limited to, IEEE 802.11ax. Asdisclosed herein, IEEE 802.11ax and HEW are synonymous.

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments. The terms “computing device”,“communication station”, “station” (STA), “handheld device”, “mobiledevice”, “wireless device” and “user equipment” (UE) as used hereinrefer to a wireless communication device such as a cellular telephone,smartphone, tablet, netbook, wireless terminal, laptop computer,femtocell, High Data Rate (HDR) subscriber station, access point, accessterminal, or other personal communication system (PCS) device. Thedevice may be either mobile or stationary.

As used within this document, the term “communicate” is intended toinclude either transmitting or receiving or both transmitting andreceiving. This may be particularly useful in claims when describing theorganization of data that is being transmitted by one device andreceived by another but only the functionality of one of those devicesis required to infringe the claim. Similarly, the bidirectional exchangeof data between two devices (both devices transmit and receive duringthe exchange) may be described as “communicating”, when only thefunctionality of one of those devices is being claimed. The term“communicating” as used herein with respect to a wireless communicationsignal includes transmitting the wireless communication signal and/orreceiving the wireless communication signal. For example, a wirelesscommunication unit, which is capable of communicating a wirelesscommunication signal, may include a wireless transmitter to transmit thewireless communication signal to at least one other wirelesscommunication unit and/or may include a wireless communication receiverto receive the wireless communication signal from at least one otherwireless communication unit.

The term “access point” (AP) as used herein may be a fixed station. Anaccess point may also be referred to as an access node, a base station,or some other similar terminology known in the art. An access terminalmay also be called a mobile station, a user equipment (UE), a wirelesscommunication device, or some other similar terminology known in theart. Embodiments disclosed herein generally pertain to wirelessnetworks. Some embodiments can relate to wireless networks that operatein accordance with one of the IEEE 802.11 standards including the IEEE802.11ax standard.

Some embodiments may be used in conjunction with various devices andsystems. Examples include: a personal computer (PC), a desktop computer,a mobile computer, a laptop computer, a notebook computer, a tabletcomputer, a server computer, a handheld computer, a handheld device, apersonal digital assistant (PDA) device, a handheld PDA device, anon-board device, an off-board device, a hybrid device, a vehiculardevice, a non-vehicular device, a mobile or portable device, a consumerdevice, a non-mobile or non-portable device, a wireless communicationstation, a wireless communication device, a wireless access point (AP),a wired or wireless router, a wired or wireless modem, a video device,an audio device, an audio-video (A/V) device, a wired or wirelessnetwork, a wireless area network, a wireless video area network (WVAN),a local area network (LAN), a wireless LAN (WLAN), a personal areanetwork (PAN), a wireless pan (WPAN), and the like.

Some embodiments may be used in conjunction with a one way and/ortwo-way radio communication system, a cellular radio-telephonecommunication system, a mobile phone, a cellular telephone, a wirelesstelephone, a personal communication systems (PCS) device, a PDA devicewhich incorporates a wireless communication device, a mobile or portableGlobal positioning system (GPS) device, a device which incorporates aGPS receiver or transceiver or chip, a device which incorporates an RFIDelement or chip, a Multiple Input Multiple Output (MIMO) transceiver ordevice, a single input multiple output (SIMO) transceiver or device, amultiple input single output (MISO) transceiver or device, a devicehaving one or more internal antennas and/or external antennas, digitalvideo broadcast (DVB) devices or systems, a multi-standard radio deviceor system, a wired or wireless handheld device, e.g., a smartphone, awireless application protocol (WAP) device, or the like.

Some embodiments may be used in conjunction with one or more types ofwireless communication signals and/or systems following one or morewireless communication protocols. Examples include: radio frequency(RF), infra-red (IR), frequency-division multiplexing (FDM), orthogonalFDM (OFDM), time-division multiplexing (TDM), time-division multipleaccess (TDMA), extended TDMA (E-TDMA), general packet radio service(GPRS), extended GPRS, code-division multiple access (CDMA), widebandCDMA (WCDMA), CDMA 2000, single-carrier CDMA, multi-carrier CDMA,multi-carrier modulation (MDM), discrete multi-tone (DMT), Bluetooth®,global positioning system (GPS), Wi-Fi, Wi-Max, ZigBee™, ultra-wideband(UWB), global system for mobile communication (GSM), 2G, 2.5G, 3G, 3.5G,4G, Fifth Generation (5G) mobile networks, 3GPP, long term evolution(LTE), LTE advanced, enhanced data rates for GSM evolution (EDGE), orthe like. Other embodiments may be used in various other devices,systems, and/or networks.

A design target for HEW is to adopt methods to improve the efficiency ofWi-Fi, and specifically the efficiency in dense deployments of Wi-Fidevices, such as in malls, conference halls, etc. HEW may use OFDMAtechniques for channel access in the uplink and downlink directions. Itis understood that the uplink direction is from a user device to an AP,and the downlink direction is from an AP to one or more user devices. Inthe uplink direction, one or more user devices may be communicating withthe AP and may be competing for channel access in a random channelaccess manner. In that case, the channel access in OFDMA may requirecoordination among the various user devices that may be competing toaccess the operating channel simultaneously. A trigger frame may consistof a preamble along with other signaling, such as resource allocation,to coordinate the uplink OFDMA operation. A trigger frame may be a framethat contains a preamble and other fields that may be sent from an APinforming all user devices serviced by the AP that channel access isavailable.

With OFDMA, the AP transmits a trigger frame allocating resources, forexample, assigning particular resources to specific stations. Individualstations use the allocated resource (e.g., 2 MHz of spectrum in aparticular portion of the channel) to transmit their data back to theAP. Therefore, with this approach, the station may only transmit anarrow bandwidth signal assigned to that station in response to atrigger frame. However, the AP does not know which stations or how manystations have data to send or how much data each of those stations mayhave to send. Accordingly, resources may be allocated to stations withno data to transmit while those with data to transmit may not receivethe resources needed to efficiently communicate its data to the AP.

The illustrative wireless network 100 of FIG. 1 may include one or moreAP(s) 102 that communicate with one or more user device(s) 120, inaccordance with IEEE 802.11 communication standards, including IEEE802.11ax. The one or more user device(s) 120 and the one or more AP's102 may be devices that are non-stationary without fixed locations ormay be stationary with fixed locations. In some embodiments, the userdevice(s) 120 and AP 102 can include one or more computer systemssimilar to that of the functional diagram of FIG. 6 and/or the examplemachine/system of FIG. 7.

In accordance with embodiments of the disclosure, the wireless network100 provides an OFDMA distributed channel access (ODCA) system thatenable random access by the user devices to the available resource unitsthat avoids the inefficiencies of scheduled allocation of the availableresources by an AP. For example, the user devices 120, including HEWuser devices, may select, which selection may be random, the particularresource to utilize for transmitting their data. However, even thoughrandom selection of resources by the user devices may be most efficientutilization of the available resources by the user devices in certaininstance, there may be other instances where it may be desirable for theuser devices to be assigned (or scheduled) access to the availableresources. Accordingly, in accordance with certain embodiments of thedisclosure, the ODCA may provide for the determination of whether toprovide random or scheduled access.

In the case of random access, an access point (e.g., AP 102) may send anaccess trigger frame (e.g., trigger frame 104) indicating that resourceunits are available for random access such that the resource units maybe selected by the user devices (e.g., user devices 124, 126 and/or 128)to send and/or receive data. For the purpose of this disclosure, wherethe trigger frame is used in connection with random access, the triggerframe may be referred to as a random trigger frame.

The resource units may be represented by RU1, RU2, . . . , RUn, where“n” is an integer. These resource units may be arranged in a sequencesuch that a user device may determine which resource unit was selectedwhen the user device is ready to transmit its data. These resource unitsmay be resources in time domain, frequency domain or a combination oftime and frequency domain. The user device may use one of these resourceunits in order to send data to an access point (e.g., AP 102).Consequently, when a user device 120 detects the trigger frame 104, theuser device 120 may identify it as a random access trigger frame. Thismay be achieved by the access point setting an identifier in the triggerframe or by other means to flag the trigger frame as a random accesstrigger frame. The user device may then select a resource unit from theresource units referenced in the trigger frame 104 by which to transmitat least a portion of its data to the AP 102. The selection of theresource unit may be done by employing various embodiments of thepresent disclosure.

The user device 120 may maintain a backoff count that may be used toselect a resource unit for transmitting the user device's uplink data ina manner that may minimize the likelihood of collision with another userdevice 120 randomly selecting the same resource unit. It is understoodthat the uplink direction may be data transmission from a user device toan access point (or other devices) and a downlink direction is the datatransmission from the access point (or other devices) to the userdevice. For example, the user device 120 may use an initial random valuefor the backoff count to determine which resource unit to select. Thebackoff count may be decremented by a first integer value until thebackoff count reaches a second integer value. For example, the backoffcount may be decrement by “1” every time the user device 120 detects aresource unit in the sequence of resource units referenced in thereceived trigger frame 104 until the backoff count reaches “0.” When thebackoff count reaches the second integer value, the user device 120 mayselect the resource unit that is associated with that backoff countvalue. In other words, the user device 120 may decrement the backoffcount every time it detects an available random access resource unituntil the backoff count reaches a predetermined integer value, which atthat time, the user device may select the resource unit that was reachedat the predetermined integer value. Since the resource units areprovided in a sequence, whenever the backoff count reaches the secondinteger value, the user device determines the resource unit in thesequence that it detected when the backoff count reached that secondinteger.

The user device(s) 120 may be assigned one or more resource units or mayrandomly access the operating channel. It is understood that a resourceunit may be bandwidth allocation on an operating channel in time and/orfrequency domain. For example, with respect to the AP assigning resourceunits, in a frequency band of 20 MHz, there may be a total of 9resources units, each of the size of a basic resource unit of 26frequency tones. The AP 102 may assign one or more of these resourceunits to one or more user device(s) 120 to transmit their uplink data.

In one embodiment, with respect to the random selection of resourceunits by devices, the AP 102 may send a trigger frame (e.g., the triggerframe 104) to one or more user device(s) 120 (e.g., the devices 124, 126and 128) indicating that resource units (e.g., RU1, RU2, . . . , RUn)are available. The user device(s) 120 may detect the trigger frame 104.The user device(s) 120 may decrement their backoff counts each time aresource unit is detected in sequence (e.g., RU1, RU2, . . . , RUn).When the backoff count of one user device reaches a predetermined value,the respective user device would utilize the equivalent resource unit totransmit data in the uplink direction. For example, if the backoff countof user device 128 was set to a value of 1, and the first detectedresource unit is RU1, the backoff count would be equal to 0 at RU2.Consequently, user device 128 may select RU2 to send its uplink data(e.g., the data 106) if it was determined that at backoff count equal to0, the user device 128 would send its data. The same may be true for theother devices serviced by an AP 102 wishing to transmit data in theuplink direction. For example, they may have backoff count of 3 oranother integer value, and when the backoff count is decremented to 0 bycounting the resource units in the trigger frame the user device mayselect the resource unit in the sequence where the backoff count becameequal to 0.

In accordance with some IEEE 802.11ax (High-Efficiency WLAN (HEW))embodiments, an access point may operate as a master station which maybe arranged to contend for a wireless medium (e.g., during a contentionperiod) to receive exclusive control of the medium for an HEW controlperiod. The master station may transmit an HEW master-sync transmissionat the beginning of the HEW control period. During the HEW controlperiod, HEW stations may communicate with the master station inaccordance with a non-contention based multiple access technique. Thisis unlike conventional Wi-Fi communications in which devices communicatein accordance with a contention-based communication technique ratherthan a multiple access technique. During the HEW control period, themaster station may communicate with HEW stations using one or more HEWframes. Furthermore, during the HEW control period, legacy stationsrefrain from communicating. In some embodiments, the master-synctransmission may be referred to as an HEW control and scheduletransmission.

In some embodiments, the multiple-access technique used during the HEWcontrol period may be a scheduled orthogonal frequency division multipleaccess (OFDMA) technique, although this is not a requirement. In otherembodiments, the multiple access technique may be a time-divisionmultiple access (TDMA) technique or a frequency division multiple access(FDMA) technique. In certain embodiments, the multiple access techniquemay be a space-division multiple access (SDMA) technique.

The master station may also communicate with legacy stations inaccordance with legacy IEEE 802.11 communication techniques. In someembodiments, the master station may also be configurable to communicatewith HEW stations outside the HEW control period in accordance withlegacy IEEE 802.11 communication techniques, although this is not arequirement.

One or more illustrative user device(s) 120 may be operable by one ormore user(s) 110. The user device(s) 120 (e.g., user devices 124, 126,and 128) may include any suitable processor-driven computing deviceincluding, but not limited to, a desktop computing device, a laptopcomputing device, a server, a router, a switch, an access point, asmartphone, a tablet, wearable wireless device (e.g., bracelet, watch,glasses, ring, etc.) and so forth.

One or more illustrative user device(s) 120 may be operable by one ormore user(s) 110. The user device(s) 120 may include any suitableprocessor-driven user device including, but not limited to, a desktopcomputing device, a laptop computing device, a server, a router, aswitch, a smartphone, a tablet, wearable wireless device (e.g.,bracelet, watch, glasses, ring, etc.) and so forth.

Any of the user device(s) (e.g., user devices 124, 126, 128) and AP 102may be configured to communicate with each other via one or morecommunications network(s) 130, either wirelessly or wired.

Any of the communications network(s) 130 may include, but is not limitedto, any one of a combination of different types of suitablecommunications networks, such as broadcasting networks, cable networks,public networks (e.g., the Internet), private networks, wirelessnetworks, cellular networks, or any other suitable private and/or publicnetworks. Further, any of the communications network(s) 130 may have anysuitable communication range associated therewith and may include, forexample, global networks (e.g., the Internet), metropolitan areanetworks (MANs), wide area networks (WANs), local area networks (LANs),or personal area networks (PANs). In addition, any of the communicationsnetwork(s) 130 may include any type of medium over which network trafficmay be carried including, but not limited to, coaxial cable,twisted-pair wire, optical fiber, a hybrid fiber coaxial (HFC) medium,microwave terrestrial transceivers, radio frequency communicationmediums, white space communication mediums, ultra-high frequencycommunication mediums, satellite communication mediums, or anycombination thereof.

Any of the user device(s) 120 (e.g., user devices 124, 126, 128) and AP102 may include one or more communications antennae. Communicationsantenna may be any suitable type of antenna corresponding to thecommunications protocols used by the user device(s) 120 (e.g., userdevices 124, 126 and 128), and AP 102. Some non-limiting examples ofsuitable communications antennas include Wi-Fi antennas, Institute ofElectrical and Electronics Engineers (IEEE) 802.11 family of standardscompatible antennas, directional antennas, non-directional antennas,dipole antennas, folded dipole antennas, patch antennas, multiple-inputmultiple-output (MIMO) antennas, or the like. The communications antennamay be communicatively coupled to a radio component to transmit and/orreceive signals, such as communications signals to and/or from the userdevice(s) 120.

Any of the user device(s) 120 (e.g., user devices 124, 126, 128) and AP102 may include any suitable radio and/or transceiver for transmittingand/or receiving radio frequency (RF) signals in the bandwidth and/orchannels corresponding to the communications protocols utilized by anyof the user device(s) 120 and AP 102 to communicate with each other. Theradio components may include hardware and/or software to modulate and/ordemodulate communications signals according to pre-establishedtransmission protocols. The radio components may further have hardwareand/or software instructions to communicate via one or more Wi-Fi and/orWi-Fi direct protocols, as standardized by the Institute of Electricaland Electronics Engineers (IEEE) 802.11 standards. In certain exampleembodiments, the radio component, in cooperation with the communicationsantennas, may be configured to communicate via 2.4 GHz channels (e.g.802.11b, 802.11g, 802.11n), 5 GHz channels (e.g. 802.11n, 802.11ac), or60 GHZ channels (e.g. 802.11ad). In some embodiments, non-Wi-Fiprotocols may be used for communications between devices, such asBluetooth, dedicated short-range communication (DSRC), Ultra-HighFrequency (UHF) (e.g. IEEE 802.11af, IEEE 802.22), white band frequency(e.g., white spaces), or other packetized radio communications. Theradio component may include any known receiver and baseband suitable forcommunicating via the communications protocols. The radio component mayfurther include a low noise amplifier (LNA), additional signalamplifiers, an analog-to-digital (A/D) converter, one or more buffers,and digital baseband.

FIG. 2 depicts an illustrative schematic diagram of an ODCA system inaccordance with one or more example embodiments of the presentdisclosure. In this illustrative example, an AP 202 may service one ormore user devices (e.g., the user devices 224 and 226).

In one embodiment, AP 202 may send a trigger frame to the one or moreuser device(s) 120 that the AP 202 services. The trigger frame indicatesto the user device(s) 120 that resource allocation is either scheduledor unscheduled (random). Based on the type of trigger frame (e.g.,scheduled or random), the user device(s) 120 may either be allocated oneor more resource units or may randomly utilize one or more resourceunits that are referenced in the trigger frame. For example, AP 202 maysend a trigger frame 210 that is dedicated for random access to userdevices 224 and 226. The trigger frame 210 may include the resourceunits (e.g., RU1, RU2, . . . , RU9) arranged in a sequence and areavailable for data transmissions that user devices 224 and 226 mayselect from to transmit UL frame 204 and UL frame 206. The userdevice(s) 120 may select one or more resource units based on a specificvalue of user device(s) 120 backoff counts. For example, user device 224having UL Frame 204 to send to AP 202, and user device 226 having ULFrame 206 to send to AP 202, may analyze their respective backoff countsto determine which resource units to use when sending their respectiveuplink data to AP 202.

In one embodiment, an AP 202 may allocate one or more random accessresource units in a trigger frame (e.g., 210). The AP 202 may flag thetrigger frame by using a predetermined identifier that identifies thetrigger frame as a random access trigger frame. For example, the triggerframe may contain an identifier that the user device may know designatesthe trigger frame as a random access trigger frame. In otherembodiments, the AP 202 may flag the trigger as a random access triggerframe by setting an Association Identifier (AID) to a value of “0”, orsome other AID value. It is understood that AID may be a number assignedto each user device 120 when the user device 120 is associated with anAP 202.

In one embodiment, an ODCA system may provide the ability for userdevices to utilize the notion of a backoff count in order to space outtheir transmissions. User devices (e.g., 224 and 226) may select randomaccess resource allocations to send their uplink data to the AP 202. Forexample, as seen in FIG. 2, the AP 202 may allocate 9 resource units(RU1, RU2, . . . , RU9), in the trigger frame 210 to be used for randomaccess. Some examples of an uplink frame may be a resource request frame(a frame that requests an additional resource unit allocation of aspecific size for additional data transfer); a management frame, such asa probe request, association request, or access network query protocol(ANQP) frame; a quality of service (QoS) data frame; or a power save(PS) poll frame (requesting that the AP 202 deliver buffered data to thestation). It is understood that the above are only examples and not tobe construed as limitations. The ODCA system may provide the ability forthe user device(s) 120 to decrement their respective backoff counts foreach resource unit detected in a trigger frame. For example, the ODCAsystem may allow a user device 120 to send its uplink data based on thevalue of its backoff count. It is understood that the backoff count maybe determined on a per user device basis. The backoff count may beindependent of other backoff counts of other user device(s) 120 becauseeach user device determines and maintains its own backoff count. It isunderstood that the above is not to be construed as a limitation andthat other counters may be utilized and maintained by one or moredevices in an ODCA system.

In one embodiment, a backoff count may be set to one or more valuesbased on various factors associated with, for example, the user device,the network, number of data transmission collisions, etc. For example, abackoff count may be set to an integer value based on whether a userdevice 120 is retransmitting its uplink data due to a previous failedattempt. The attempt may have failed due to collisions, noise, networkfailure, etc. Further, the backoff count may be set to an integer basedon whether an uplink data transmission was successful and reached anintended destination (e.g., AP 202). It is understood that the above areonly some examples that a retransmission of uplink data may occur andthat other reasons may cause a retransmission.

In one or more embodiments, the backoff count may be based on anotherinteger value that may be associated with a user device 120. Forexample, the backoff count of a user device 120 may be based on aContention Window for OFDMA (CWO) integer value. The CWO may have aminimum value (CWO_min) and a maximum value (CWO_max), which may beintegers. The CWO value may be set by the ODCA system, by anadministrator, and/or by a user 110. It is understood that the CWO valuemay be determined in such a way to produce the least collisions and/orretransmissions in a network. For example, in order to minimizecollisions, the CWO may be determined to be a predetermined integer. Forexample, CWO may be set to a multiple of “2” minus “1.” It is understoodthat the above is only for illustrative purposes and that CWO may be setto other values. The determination of the CWO values and the backoffcount may be set by the ODCA system automatically, by an administrator,or by the user 110. It is understood that above are only examples andthat CWO may be set to other values as needed.

In one embodiment, the resource units selected may be based on a backoffcount associated with a user device 120, which may be decremented foreach resource unit identified in the received trigger frame. Forexample, when user devices 224 and/or 226 receive the trigger frame 210,which provides random access resource units (e.g., RU1, RU2, . . . ,RU9), the user devices 224 and/or 226 may decrement their backoff countsfor each random access resource unit they detect in this sequence. Theamount of decrementing the backoff count may be a first predeterminedinteger number that may be set by the ODCA system, by an administrator,and/or by a user 110. For example, the backoff count of user devices 224and/or 226 may be decremented by an integer value of “1” every time aresource unit is detected in the same sequence they are provided by thetrigger frame. In this case, detecting RU1 causes the backoff count ofuser device 224 to decrement by “1,” and when the user device 224detects RU2, it may decrement the backoff count by “1” again, and so on.

In one embodiment, the backoff count may be decremented until reaching asecond predetermined integer. For example, if the backoff count isdecremented by “1” for each random access resource unit the user device120 detects, the user device 120 may select the corresponding resourceunit when the backoff count reaches the second predetermined integer.Assuming the first predetermined integer is “3” and the secondpredetermined integer is “0,” the user device 224 may decrement itsbackoff count by “1” for each random access resource unit it detects andmay select the resource unit that corresponds to a backoff count equalto “0,” which in this example would be the third resource unit.

In one embodiment, a user device 120 may transmit its uplink data usinga random access resource unit whenever its backoff count reaches thesecond predetermined integer value. For example, looking at user device226, upon receiving the trigger frame 210, the user device 226 maydecrement its backoff time by “1” every time it detects a random accessresource unit (e.g., RU1, RU2, . . . , RU9). The user device 226 may usethe resource unit where the value of its backoff count reaches the value“0.” For example, if the backoff count for user device 226 was “3,” andthere were 9 resource units (e.g., RU1, RU2, . . . , RU9) indicated inthe trigger frame 210, the backoff reaches the value of “0” at RU4.Therefore, user device 226 may transmit its UL frame 206 using RU4.

In one embodiment, the ODCA system may provide the ability for a userdevice(s) 120 to select the first resource unit in the sequence ofresource units (e.g., RU1, RU2, . . . , RU9) whenever the backoff countof the user device(s) 120 is initialized to a value of “0.” In thiscase, there is no need to decrement the backoff count. For example, ifthe backoff count of user device 226 is “0,” and the AP 202 sent atrigger frame 210 with resource units RU1, RU2, . . . , RU9 arranged inthat sequence, the user device 226 may select RU1 for transmitting itsdata since RU1 is the first resource unit in that sequence.

In one embodiment, if AP 202 received the uplink data from a user device120, the AP 202 may respond to the user device 120 with anacknowledgment (ACK) indicating that it received the uplink data. In oneembodiment, if the user device 120 receives that ACK from the AP 202,the value for CWO may be set to CWO_min. On the other hand, if the userdevice 120 does not receive an ACK, CWO may be set to an integer valuethat may be based on factors such as retransmission, network congestion,environment, etc. For example, CWO may be set to min(2×CWO-1, CWO_max).It is understood that the above are only for illustrative purposes andthat CWO may be set to other values. The determination of the CWO valuesand the backoff count may be set by the ODCA system automatically, by anadministrator, or by the user 110. It is understood that above are onlyexamples and that CWO may be set to other values as needed.

FIG. 3 depicts an example ODCA system in accordance with one or moreembodiments of the disclosure. It is understood that the example in FIG.3 is mainly for illustrative purposes only and that other scenarios maybe envisioned. For example, assume that four user devices (e.g., 304,306, 308, and 310) have data to send. At the time each user deviceidentifies that it has data to send, it may select a random value forits backoff count between 0 and CWO. In this example, assume that userdevice 304 has a backoff count equal to “0,” user device 306 has abackoff count equal to “3,” user device 308 has a backoff count equal to“10,” and user device 310 has a backoff count equal to “17.”

Upon receiving the trigger frame (e.g., 305), user device 304 maydetermine that random access resource units (e.g., RU1, RU2, . . . RU9)have been allocated for uplink access by the AP 302. Since its backoffcount is equal to “0,” it may select the first random access resourceunit (RU1) for its transmission. When user device 306 receives thetrigger frame 305, it too determines that random access resource units(e.g., RU1, RU2, . . . RU9) have been allocated. It may decrement itsbackoff count for each random access RU it sees. When it reaches RU4,its backoff count is equal to “0” and it may select RU4 for itstransmission.

Continuing with this example, user device 308 and user device 310 maydecrement their backoff counts for each random access resource unit(e.g., RU1, RU2, . . . RU9) they detect in trigger frame 305. Afterreaching RU9 in the trigger frame 305, the final random accessallocation in the first trigger frame, user device 308 backoff count isnow equal to “1” and user device 310 backoff count is equal to “8.” Userdevices 304 and 306 may transmit their uplink frames (e.g., 312 and 314)using their selected resources (e.g., RU1 and RU4). Since user devices304 and 306 are using different resource units, collision may beavoided. As a result, the AP 302 may successfully receive the uplinkframes (e.g., 312 and 314) and send ACK 320 to user device 304 and ACK322 to user device 306 in response to receiving uplink frames 312 and314 respectively. Upon receiving ACK 320, user device 304 may set itsCWO to CWO_min. The same thing happens with user device 306 uponreceiving ACK 322. In case user devices 304 and 306 have additionaluplink data to send, they may select a new random integer between 0 andCWO for their backoff count, and the process may repeat by decrementingthe backoff count for each random access resource unit detected in a newtrigger frame.

Continuing with this example, with user devices 308 and 310, when thesecond trigger frame (e.g., 324) is detected, user devices 308 and 310may continue decrementing their backoff count values. For example, thebackoff count for user device 308 may reach the value of “0” at resourceunit RU11. As for user device 310, its backoff count may reach “0” atresource unit RU18. Since user devices 308 and 310 may be usingdifferent resource units (e.g., RU11 and RU18), collision may beavoided. As a result, the AP 302 may successfully receive the uplinkframes (e.g., 316 and 318) and send ACK 326 to user device 308 and ACK328 to user device 310 in response to receiving uplink frames 316 and318 respectively. Upon receiving these ACKs, the user devices 308 and310 may reset their respective CWO values to CWO_min and select newbackoff count values between 0 and CWO.

In another embodiment, if two (or more) user devices identify the samerandom access resource unit for their uplink data transmission, theremay be a collision (e.g., both user devices transmitting using the sameresource) and likely the AP 302 may be unable to successfully demodulateone of the transmissions. As a result, the AP 302 may not transmit anACK to at least one of the user devices. In that case, the user devicesmay not receive the ACK and may in that case set their respective CWO toa different value due to a need to retransmit the uplink frame. The CWOmay be set to an integer value that may be appropriate for the networkand/or the user device. For example, in some embodiments, the CWO may beset to the min(2×CWO-1, CWO_max) or may be set to min(CWO×R−1), where Ris the number of retransmissions.

In another embodiment, an exponential backoff technique may be used toreduce the collision rate when a large number of user devices areactive. This may help space out repeated transmissions of the same dataframe in order to alleviate network congestion. For example, the CWO maybe set to min (CWO×2^(R)−1), where R is an integer representing thenumber of retransmissions. Further, the user devices may select newrandom values between 0 and CWO for their backoff count. The process mayrepeat by decrementing the backoff count for each random access resourceunit detected in a new trigger frame. This continues until a user deviceis able to successfully transmit its uplink data and receive an ACK fromAP 302.

In some embodiments, the retransmission may be limited to apredetermined number. For example, retransmission may be aborted if thenumber of retransmissions reaches a threshold integer value. Forexample, after 15 attempts to retransmit a failed uplink transmission, auser device may stop the retransmission process and may announce to thenetwork that access is denied. It is understood that the above is onlyan example, and that the number of retransmissions may be different. Thethreshold may be set by the ODCA system automatically, by anadministrator, or by the user 110.

FIG. 4 illustrates a flow diagram of illustrative process 400 for anOFDMA distributed channel access system in accordance with one or moreembodiments of the disclosure.

At block 402, the AP 102 may determine one or more random accessresource allocations. These allocations may be random such that a userdevice 120 may randomly access a communication channel establishedbetween the AP 102 and user device 120 in order to transmit its data.These one or more random access resource allocations are in accordancewith Orthogonal Frequency Division Multiplex (OFDMA) standard such thatthe resources are in frequency domain, time domain, or a combination ofboth. In order to determine that these resource allocations are forrandom access, the AP 102 may use an Association Identifier (AID) equalto “0” or an AID not associated with the one or more user devices or anpredetermined identifier to flag the trigger frame as a random accesstrigger frame. In that case, a user device 120 may determine that theseresources are allocated for random access.

At block 404, the AP 102 may generate a trigger frame associated withthe one or more random access resource allocations. The trigger frameindicates to the user device(s) 120 serviced by the AP 102 that resourceunits are allocated for random access.

At block 406, the AP 102 may send the trigger frame to the userdevice(s) 120 such that the user device(s) 120 are able to select one ormore of the resource allocations to transmit their uplink data. However,there is a possibility of two or more user device(s) 120 selecting thesame resource unit that was allocated by the AP 102.

At block 408, the AP 102 receives from a user device 120 an uplink framebased on a first backoff count associated with the user device inresponse to sending the trigger frame. For example, the user device 120may maintain a backoff count that is set to an integer value based onvarious factors such as whether a user device 120 is retransmitting itsuplink data due to a previous failed attempt. The attempt may havefailed due to collisions, noise, network failure, etc. Further, thebackoff count may be set to an integer based on whether an uplink datatransmission was successful and reached an intended destination (e.g.,AP 102). Based on the value of the backoff count, a user device 120 mayselect one of the resource units associated with a trigger frame thatwas sent by the AP 102. The user device then utilizes the selectedresource unit to send its uplink data to the AP 102. In return, the AP102, upon receiving the uplink data from the user device 120, may sendan acknowledgment (ACK) to the user device that the uplink data wasreceived.

FIG. 5 illustrates a flow diagram of illustrative process 500 for anOFDMA distributed channel access system in accordance with one or moreembodiments of the disclosure.

At block 502, the user device(s) 120 may initialize a backoff count to acontention window (CWO) value. The CWO may also have a minimum value(CWO_min) and a maximum value (CWO_max), which may be integers. The CWOvalue may be set by the ODCA system, by an administrator, and/or by auser 110. It is understood that the CWO value may be determined in sucha way to produce the least collisions and/or retransmissions in anetwork. For example, in order to minimize collisions, the CWO may bedetermined to be an integer that is a multiple of “2” minus “1.”

At block 504, a user device 120 may receive, on a communication channel,at least one trigger frame from an AP 102. For example, the AP 102generates the trigger frame with one or more allocated random accessresource units. The AP 102 may send the trigger frame to all the userdevice(s) 120 that it services.

At block 506, a user device 120 may detect one or more random accessresource units associated with the trigger frame. For example, the userdevice 120 may analyze the trigger frame to determine the one or moreresource units that are associated with that trigger frame. Since thebackoff count was initialized to a certain integer value, the userdevice 120 may utilize that backoff count in order to make its selectionof one of the random access resource units.

At block 508, the user device(s) 120 may decrement a backoff count by aninteger for each of the detected random access resource units. Forexample, if the backoff count of a user device 120 was initialized to aninteger value of “3”, and if the trigger frame referenced 9 resourceunits (e.g., RU1, RU2, . . . , RU9), the user device 120 may decrementthe backoff count for each resource unit it detects.

At block 510, the user device(s) 120 may determine a resource allocationof the one or more random access resource allocations associated withthe backoff count being equal to a second integer. For example, if thebackoff count may be decremented to reach the value of “0” for each ofthe detected resource units, the user device may select that resourceunit. Continuing with the above example, since the backoff count is “3”and there are 9 resource units associated with the received triggerframe, the user device 120 may select the fourth resource unit (e.g.,RU4) found in the sequence of resource units associated with the triggerframe. This is the case because for the first resource unit, the backoffcount was “3”, for the second resource unit, the backoff count was “2,”for the third resource unit, the backoff count was “1,” and for thefourth resource unit, the backoff count was “0.” Therefore, the userdevice 120 may select that resource unit (e.g., RU4) since at thatpoint, the backoff count was equal to “0.” It is understood that theselection of a resource unit may be when the backoff count is equal toother than the value of “0,” and that it could be for other integervalues that may be determined by the system, by an administrator, or bythe user.

At block 512, the user device(s) 120 may send an uplink frame using thefirst resource allocation to the computing device. In the above example,it was determined that the user device 120 may send its uplink datausing the fourth resource unit (e.g., RU4). After sending its uplinkdata, the user device 120 may monitor the communication channel for anACK from the AP 102.

If the backoff count did not reach the value of “0,” for example, beforegoing through the entire sequence of resource units (e.g., RU1, RU2, . .. , RU9), the user device may wait for another trigger frame from the AP102 where more random access resource units are allocated before sendingits uplink data. For example, assuming the backoff count was initializedto be “10,” the first trigger frame only contained 9 resource units(RU1, RU2, . . . , RU9) and therefore, the backoff count would not reachthe value “0” from only the first trigger frame. However, upon receivinga second trigger frame from AP 102, the user device 120 may be able toselect the second resource unit of the second trigger frame because atthat point, the backoff count would have reached the value of “0.”

If the user device 120 does not receive an ACK from the AP 102, the userdevice 120 may set the value of CWO to a different value due to a needto retransmit the uplink frame. The CWO may be set to an integer valuethat may be appropriate for the network and/or the user device. Forexample, in some embodiments, the CWO may be set to min(2×CWO-1,CWO_max) or may be set to min(CWO×R−1), where R is the number ofretransmissions. In another embodiment, the CWO may be set to min(CWO×2^(R)−1), where R is an integer representing the number ofretransmissions. Accordingly, the user devices may select new randomvalues between 0 and CWO for their backoff count. The process may repeatby decrementing the backoff count for each random access resource unitdetected in a new trigger frame. This continues until a user device 120is able to successfully transmit its uplink data and receive an ACK fromAP 102.

If however, an ACK is received from the AP 102, the user device 120 mayset the CWO to a CWO_min, where CWO_min is a minimum value of the CWO.

FIG. 6 shows a functional diagram of an exemplary communication station800 in accordance with some embodiments. In one embodiment, FIG. 6illustrates a functional block diagram of a communication station thatmay be suitable for use as an AP 102 (see, FIG. 1) or user device(s) 120(see, FIG. 1) in accordance with some embodiments. The communicationstation 800 may also be suitable for use as a handheld device, mobiledevice, cellular telephone, smartphone, tablet, netbook, wirelessterminal, laptop computer, wearable computer device, femtocell, HighData Rate (HDR) subscriber station, access point, access terminal, orother personal communication system (PCS) device.

The communication station 800 may include physical layer circuitry 802,having a transceiver 810 for transmitting and receiving signals to andfrom other communication stations using one or more antennas 801. Thephysical layer circuitry 802 may also include medium access control(MAC) circuitry 804 for controlling access to the wireless medium. Thecommunication station 800 may also include processing circuitry 806 andmemory 808 arranged to perform the operations described herein. In someembodiments, the physical layer circuitry 802 and the processingcircuitry 806 may be configured to perform operations detailed in FIGS.2-5.

In accordance with some embodiments, the MAC circuitry 804 may bearranged to contend for a wireless medium and configure frames orpackets for communicating over the wireless medium, and the physicallayer circuitry 802 may be arranged to transmit and receive signals. Thephysical layer circuitry 802 may include circuitry formodulation/demodulation, upconversion/downconversion, filtering,amplification, etc. In some embodiments, the processing circuitry 806 ofthe communication station 800 may include one or more processors. Inother embodiments, two or more antennas 801 may be coupled to thephysical layer circuitry 802 arranged for sending and receiving signals.The memory 808 may store information for configuring the processingcircuitry 806 to perform operations for configuring and transmittingmessage frames and performing the various operations described herein.The memory 808 may include any type of memory, including non-transitorymemory, for storing information in a form readable by a machine (e.g., acomputer). For example, the memory 808 may include a computer-readablestorage device, read-only memory (ROM), random access memory (RAM),magnetic disk storage media, optical storage media, flash-memory devicesand other storage devices and media.

In some embodiments, the communication station 800 may be part of aportable wireless communication device, such as a personal digitalassistant (PDA), a laptop or portable computer with wirelesscommunication capability, a web tablet, a wireless telephone, asmartphone, a wireless headset, a pager, an instant messaging device, adigital camera, an access point, a television, a medical device (e.g., aheart rate monitor, a blood pressure monitor, etc.), a wearable computerdevice, or another device that may receive and/or transmit informationwirelessly.

In some embodiments, the communication station 800 may include one ormore antennas 801. The antennas 801 may include one or more directionalor omnidirectional antennas, including, for example, dipole antennas,monopole antennas, patch antennas, loop antennas, microstrip antennas,or other types of antennas suitable for transmission of RF signals. Insome embodiments, instead of two or more antennas, a single antenna withmultiple apertures may be used. In these embodiments, each aperture maybe considered a separate antenna. In some multiple-input multiple-output(MIMO) embodiments, the antennas may be effectively separated forspatial diversity and the different channel characteristics that mayresult between each of the antennas and the antennas of a transmittingstation.

In some embodiments, the communication station 800 may include one ormore of a keyboard, a display, a non-volatile memory port, multipleantennas, a graphics processor, an application processor, speakers, andother mobile device elements. The display may be an LCD screen includinga touch screen.

Although the communication station 800 is illustrated as having severalseparate functional elements, two or more of the functional elements maybe combined and may be implemented by combinations ofsoftware-configured elements, such as processing elements includingdigital signal processors (DSPs), and/or other hardware elements. Forexample, some elements may include one or more microprocessors, DSPs,field-programmable gate arrays (FPGAs), application specific integratedcircuits (ASICs), radio-frequency integrated circuits (RFICs) andcombinations of various hardware and logic circuitry for performing atleast the functions described herein. In some embodiments, thefunctional elements of the communication station 800 may refer to one ormore processes operating on one or more processing elements.

Certain embodiments may be implemented in one or a combination ofhardware, firmware, and software. Other embodiments may also beimplemented as instructions stored on a computer-readable storagedevice, which may be read and executed by at least one processor toperform the operations described herein. A computer-readable storagedevice may include any non-transitory memory mechanism for storinginformation in a form readable by a machine (e.g., a computer). Forexample, a computer-readable storage device may include read-only memory(ROM), random-access memory (RAM), magnetic disk storage media, opticalstorage media, flash-memory devices, and other storage devices andmedia. In some embodiments, the communication station 800 may includeone or more processors and may be configured with instructions stored ona computer-readable storage device.

FIG. 7 illustrates a block diagram of an example of a machine 900 orsystem upon which any one or more of the techniques (e.g.,methodologies) discussed herein may be performed. In other embodiments,the machine 900 may operate as a standalone device or may be connected(e.g., networked) to other machines. In a networked deployment, themachine 900 may operate in the capacity of a server machine, a clientmachine, or both in server-client network environments. In an example,the machine 900 may act as a peer machine in peer-to-peer (P2P) (orother distributed) network environments. The machine 900 may be apersonal computer (PC), a tablet PC, a set-top box (STB), a personaldigital assistant (PDA), a mobile telephone, wearable computer device, aweb appliance, a network router, switch or bridge, or any machinecapable of executing instructions (sequential or otherwise) that specifyactions to be taken by that machine, such as a base station. Further,while only a single machine is illustrated, the term “machine” shallalso be taken to include any collection of machines that individually orjointly execute a set (or multiple sets) of instructions to perform anyone or more of the methodologies discussed herein, such as cloudcomputing, software as a service (SaaS), or other computer clusterconfigurations.

Examples, as described herein, may include or may operate on logic or anumber of components, modules, or mechanisms. Modules are tangibleentities (e.g., hardware) capable of performing specified operationswhen operating. A module includes hardware. In an example, the hardwaremay be specifically configured to carry out a specific operation (e.g.,hardwired). In another example, the hardware may include configurableexecution units (e.g., transistors, circuits, etc.) and a computerreadable medium containing instructions where the instructions configurethe execution units to carry out a specific operation when in operation.The configuring may occur under the direction of the executions units ora loading mechanism. Accordingly, the execution units arecommunicatively coupled to the computer-readable medium when the deviceis operating. In this example, the execution units may be a member ofmore than one module. For example, under operation, the execution unitsmay be configured by a first set of instructions to implement a firstmodule at one point in time and reconfigured by a second set ofinstructions to implement a second module at a second point in time.

The machine (e.g., computer system) 900 may include a hardware processor902 (e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 904 and a static memory 906, some or all of which may communicatewith each other via an interlink (e.g., bus) 908. The machine 900 mayfurther include a power management device 932, a graphics display device910, an alphanumeric input device 912 (e.g., a keyboard), and a userinterface (UI) navigation device 914 (e.g., a mouse). In an example, thegraphics display device 910, alphanumeric input device 912, and UInavigation device 914 may be a touch screen display. The machine 900 mayadditionally include a storage device (i.e., drive unit) 916, a signalgeneration device 918 (e.g., a speaker), a resource unit selectiondevice 919, a network interface device/transceiver 920 coupled toantenna(s) 930, and one or more sensors 928, such as a globalpositioning system (GPS) sensor, compass, accelerometer, or othersensor. The machine 900 may include an output controller 934, such as aserial (e.g., universal serial bus (USB), parallel, or other wired orwireless (e.g., infrared (IR), near field communication (NFC), etc.)connection to communicate with or control one or more peripheral devices(e.g., a printer, card reader, etc.)).

The storage device 916 may include a machine readable medium 922 onwhich is stored one or more sets of data structures or instructions 924(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 924 may alsoreside, completely or at least partially, within the main memory 904,within the static memory 906, or within the hardware processor 902during execution thereof by the machine 900. In an example, one or anycombination of the hardware processor 902, the main memory 904, thestatic memory 906, or the storage device 916 may constitutemachine-readable media.

The resource unit selection device 919 may be configured to select arandom access resource unit associated with a detected random accesstrigger frame. The resource unit selection device 919 may maintain abackoff count that may be used to select a resource unit fortransmitting a user device's uplink data. For example, the resource unitselection device 919 may use an initial random value for the backoffcount to determine which resource unit to select. The backoff count maybe decremented by a first integer value until the backoff count reachesa second integer value. When the backoff count reaches the secondinteger value, the user device would select the resource unit that isassociated with that backoff count value. In other words, the resourceunit selection device 919 would decrement the backoff count every timeit detects an available random access resource unit. Since the resourceunits are provided in a sequence, whenever the backoff count reaches thesecond integer value, the resource unit selection device 919 determinesthe resource unit in the sequence that it detected when the backoffcount reached that second integer. For example, if the initial value ofthe backoff count is 2, there were 9 resource units (RU1, RU2, . . . ,RU9) referenced in the trigger frame, the second integer value was 0,and the first integer value for decrementing the backoff count is 1,then the backoff count would reach the value 0 at resource unit RU3.Consequently, the user device may select RU3 to transmit its uplinkdata.

While the machine-readable medium 922 is illustrated as a single medium,the term “machine-readable medium” may include a single medium ormultiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) configured to store the one or moreinstructions 924.

The term “machine-readable medium” may include any medium that iscapable of storing, encoding, or carrying instructions for execution bythe machine 900 and that cause the machine 900 to perform any one ormore of the techniques of the present disclosure, or that is capable ofstoring, encoding, or carrying data structures used by or associatedwith such instructions. Non-limiting machine-readable medium examplesmay include solid-state memories and optical and magnetic media. In anexample, a massed machine-readable medium includes a machine-readablemedium with a plurality of particles having resting mass. Specificexamples of massed machine-readable media may include non-volatilememory, such as semiconductor memory devices (e.g., ElectricallyProgrammable Read-Only Memory (EPROM), or Electrically ErasableProgrammable Read-Only Memory (EEPROM)) and flash memory devices;magnetic disks, such as internal hard disks and removable disks;magneto-optical disks; and CD-ROM and DVD-ROM disks.

The instructions 924 may further be transmitted or received over acommunications network 926 using a transmission medium via the networkinterface device/transceiver 920 utilizing any one of a number oftransfer protocols (e.g., frame relay, internet protocol (IP),transmission control protocol (TCP), user datagram protocol (UDP),hypertext transfer protocol (HTTP), etc.). Example communicationsnetworks may include a local area network (LAN), a wide area network(WAN), a packet data network (e.g., the Internet), mobile telephonenetworks (e.g., cellular networks), Plain Old Telephone (POTS) networks,wireless data networks (e.g., Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 family of standards known as Wi-Fi®, IEEE 802.16family of standards known as WiMax®), IEEE 802.15.4 family of standards,and peer-to-peer (P2P) networks, among others. In an example, thenetwork interface device/transceiver 920 may include one or morephysical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or moreantennas to connect to the communications network 926. In an example,the network interface device/transceiver 920 may include a plurality ofantennas to wireles sly communicate using at least one of single-inputmultiple-output (SIMO), multiple-input multiple-output (MIMO), ormultiple-input single-output (MISO) techniques. The term “transmissionmedium” shall be taken to include any intangible medium that is capableof storing, encoding, or carrying instructions for execution by themachine 900 and includes digital or analog communications signals orother intangible media to facilitate communication of such software.

According to example embodiments of the disclosure, there may be adevice. The device may include a transceiver configured to transmit andreceive wireless signals, an antenna coupled to the transceiver, one ormore processors in communication with the transceiver, at least onememory that stores computer-executable instructions, and at least oneprocessor of the one or more processors configured to access the atleast one memory. The at least one processor of the one or moreprocessors may be configured to execute the computer-executableinstructions to determine a first uplink frame to be sent to a computingdevice on a communication channel. The at least one processor of the oneor more processors may be configured to execute the computer-executableinstructions to identify at least one trigger frame received on thecommunication channel from the computing device. The at least oneprocessor of the one or more processors may be configured to execute thecomputer-executable instructions to identify one or more first randomaccess resource allocations, including a first resource allocation and alast resource allocation, wherein the one or more first random accessresource allocations are associated with a first trigger frame of the atleast one trigger frame. The at least one processor of the one or moreprocessors may be configured to execute the computer-executableinstructions to determine a backoff count, the backoff count based atleast in part on a integer value associated with Orthogonal FrequencyDivision Multiple Access (OFDMA), the backoff count having an initialbackoff count. The at least one processor of the one or more processorsmay be configured to execute the computer-executable instructions todecrement the backoff count by a first integer, for each of theidentified one or more first random access resource allocations. The atleast one processor of the one or more processors may be configured toexecute the computer-executable instructions to determine a resourceallocation of the one or more first random access resource allocationsassociated with the backoff count being equal to a second integer. Theat least one processor of the one or more processors may be configuredto execute the computer-executable instructions to cause to send thefirst uplink frame using the resource allocation to the computingdevice. The integer value associated with OFDMA may be a contentionwindow (CW) for Orthogonal Frequency Division Multiplex. The resourceallocation may be the first resource allocation when the initial backoffcount is equal to 0. The at least one processor of the one or moreprocessors may be further configured to execute the computer-executableinstructions to identify, in response to sending the first uplink frame,an acknowledgment from the computing device. The at least one processorof the one or more processors may be further configured to execute thecomputer-executable instructions to determine the initial backoff countis greater than or equal to a count of the one or more first randomaccess resource allocations associated with the first trigger frame. Theat least one processor of the one or more processors may be furtherconfigured to execute the computer-executable instructions to detect oneor more second random access resource allocations arranged in sequence,associated with a second trigger frame of the at least one triggerframe. The at least one processor of the one or more processors may befurther configured to execute the computer-executable instructions todecrement the backoff count by the first integer for each detectedsecond random access resource allocations. The at least one processor ofthe one or more processors may be further configured to execute thecomputer-executable instructions to determine a second resourceallocation in the second trigger frame, associated with the backoffcount being equal to the second integer. The initial backoff count maybe initialized to a random integer value between 0 and the contentionwindow (CW). The at least one processor of the one or more processorsmay be further configured to execute the computer-executableinstructions to determine an acknowledgment is not received from thecomputing device. The at least one processor of the one or moreprocessors may be further configured to execute the computer-executableinstructions to set the CW to the minimum of 2×CW-1 and CW_MAX, whereinCW_MAX is a maximum value of the CW based at least in part on thedevice. The at least one processor of the one or more processors may befurther configured to execute the computer-executable instructions todetermine when an acknowledgment is received from the computing device.The at least one processor of the one or more processors may be furtherconfigured to execute the computer-executable instructions to set theCWO to a CWO_MIN, where CWO_MIN is a minimum value of the CWO based atleast in part on the device.

In example embodiments of the disclosure, there may be a non-transitorycomputer-readable medium storing computer-executable instructions which,when executed by a processor, cause the processor to perform operations.The operations may include determining one or more random accessresource allocations including a first resource allocation. Theoperations may include generating a trigger frame associated with theone or more random access resource allocations. The operations mayinclude causing to send the trigger frame to one or more user devicesincluding a first user device. The operations may include receiving fromthe first user device, in response to sending the trigger frame, a firstuplink frame using the first resource allocation, based at least in parton a first backoff count associated with the first user device. Thefirst backoff count may be initialized to a random integer value between0 and a contention window (CW) for orthogonal frequency divisionmultiplex. The operations may further include sending, in response toreceiving the first uplink frame, a first acknowledgment to the firstuser device. The one or more random access resource allocations mayinclude at least one of a random access trigger frame identifier, anAssociation Identifier (AID) equal to 0, or an AID not associated withthe one or more user devices. The first resource allocation may beassociated with the first backoff count being equal to a first integer.The first backoff count may be re-initialized to a random integer valuebetween 0 and CWO after receiving the first uplink frame from the firstuser device.

In example embodiments of the disclosure, there may be a method. Themethod may include determining, by a first computing device includingone or more processors and one or more transceiver components, one ormore random access resource allocations. The method may includegenerating a trigger frame associated with the one or more random accessresource allocations. The method may include causing to send, by thefirst computing device, the trigger frame to one or more user devicesincluding a first user device. The method may include receiving, by thefirst computing device, from the first user device, in response tosending the trigger frame, a first uplink frame based on a first backoffcount associated with the first user device. The one or more randomaccess resource allocations may be in accordance with OrthogonalFrequency Division Multiplex (OFDMA) standard. The method may furtherinclude sending, in response to receiving the first uplink frame, afirst acknowledgment to the first user device. The one or more randomaccess resource allocations may include at least one of a random accesstrigger frame identifier, an Association Identifier (AID) equal to 0, oran AID not associated with the one or more user devices. One of the oneor more random access resource allocations may be associated with thefirst backoff count being equal to a first integer.

In example embodiments of the disclosure, there may be a wirelesscommunication apparatus. The apparatus may include a means fordetermining, by a first computing device including one or moreprocessors and one or more transceiver components, a first uplink frameto be sent to a computing device on a communication channel. Theapparatus may include a means for identifying, by the first computingdevice, at least one trigger frame received on the communication channelfrom the computing device. The apparatus may include a means foridentifying, by the first computing device, one or more first randomaccess resource allocations, including a first resource allocation and alast resource allocation, wherein the one or more first random accessresource allocations are associated with a first trigger frame of the atleast one trigger frame. The apparatus may include a means fordetermining, by the first computing device, a backoff count, the backoffcount based at least in part on a integer value associated withOrthogonal Frequency Division Multiple Access (OFDMA), the backoff counthaving an initial backoff count. The apparatus may include a means fordecrementing, by the first computing device, the backoff count by afirst integer, for each of the identified one or more first randomaccess resource allocations. The apparatus may include a means fordetermining, by the first computing device, a resource allocation of theone or more first random access resource allocations associated with thebackoff count being equal to a second integer. The apparatus may includea means for causing to send, by the first computing device, the firstuplink frame using the resource allocation to the computing device. Theinteger value associated with OFDMA may be a contention window (CW) forOrthogonal Frequency Division Multiplex. The resource allocation may bethe first resource allocation when the initial backoff count is equal to0. The apparatus may further include a means for identifying, by thefirst computing device, in response to sending the first uplink frame,an acknowledgment from the computing device. The apparatus may furtherinclude a means for determining, by the first computing device, theinitial backoff count is greater than or equal to a count of the one ormore first random access resource allocations associated with the firsttrigger frame. The apparatus may further include a means for detecting,by the first computing device, one or more second random access resourceallocations arranged in sequence, associated with a second trigger frameof the at least one trigger frame. The apparatus may further include ameans for decrementing, by the first computing device, the backoff countby the first integer for each detected second random access resourceallocations. The apparatus may further include a means for determining,by the first computing device, a second resource allocation in thesecond trigger frame, associated with the backoff count being equal tothe second integer. The initial backoff count may be initialized to arandom integer value between 0 and the contention window (CW). Theapparatus may further include a means for determining, by the firstcomputing device, an acknowledgment is not received from the computingdevice. The apparatus may further include a means for setting, by thefirst computing device, the CW to the minimum of 2×CW-1 and CW_MAX,wherein CW_MAX is a maximum value of the CW based at least in part onthe device. The apparatus may further include a means for determiningwhen an acknowledgment may be received from the computing device. Theapparatus may further include setting the CWO to a CWO_MIN, whereCWO_MIN is a minimum value of the CWO based at least in part on thedevice.

In example embodiments of the disclosure, there may be a wirelesscommunication system. The system may include at least one memory thatstore computer-executable instructions, and at least one processorconfigured to access the at least one memory. The at least one processormay be configured to execute the computer-executable instructions todetermine one or more random access resource allocations including afirst resource allocation. The at least one processor may be configuredto execute the computer-executable instructions to generate a triggerframe associated with the one or more random access resourceallocations. The at least one processor may be configured to execute thecomputer-executable instructions to cause to send the trigger frame toone or more user devices including a first user device. The at least oneprocessor may be configured to execute the computer-executableinstructions to receive from the first user device, in response tosending the trigger frame, a first uplink frame using the first resourceallocation, based at least in part on a first backoff count associatedwith the first user device. The first backoff count may be initializedto a random integer value between 0 and a contention window (CW) fororthogonal frequency division multiplex. The at least one processor maybe further configured to execute the computer-executable instructions tosend, in response to receiving the first uplink frame, a firstacknowledgment to the first user device. The one or more random accessresource allocations may include at least one of a random access triggerframe identifier, an Association Identifier (AID) equal to 0, or an AIDnot associated with the one or more user devices. The first resourceallocation may be associated with the first backoff count being equal toa first integer. The first backoff count may be re-initialized to arandom integer value between 0 and CWO after receiving the first uplinkframe from the first user device.

In example embodiments of the disclosure, there may be a wirelesscommunication apparatus. The apparatus may include a means fordetermining, by a first computing device including one or moreprocessors and one or more transceiver components, one or more randomaccess resource allocations including a first resource allocation. Theapparatus may include a means for generate, by the first computingdevice, a trigger frame associated with the one or more random accessresource allocations. The apparatus may include a means for causing tosend, by the first computing device, the trigger frame to one or moreuser devices including a first user device. The apparatus may include ameans for receiving, from the first user device, in response to sendingthe trigger frame, a first uplink frame using the first resourceallocation, based at least in part on a first backoff count associatedwith the first user device. The first backoff count may be initializedto a random integer value between 0 and a contention window (CW) fororthogonal frequency division multiplex. The apparatus may furtherinclude a means for sending, by the first computing device, in responseto receiving the first uplink frame, a first acknowledgment to the firstuser device. The one or more random access resource allocations mayinclude at least one of a random access trigger frame identifier, anAssociation Identifier (AID) equal to 0, or an AID not associated withthe one or more user devices. The first resource allocation may beassociated with the first backoff count being equal to a first integer.The first backoff count may be re-initialized to a random integer valuebetween 0 and CWO after receiving the first uplink frame from the firstuser device.

The operations and processes described and shown above may be carriedout or performed in any suitable order as desired in variousimplementations. Additionally, in certain implementations, at least aportion of the operations may be carried out in parallel. Furthermore,in certain implementations, less than or more than the operationsdescribed may be performed.

Certain aspects of the disclosure are described above with reference toblock and flow diagrams of systems, methods, apparatuses, and/orcomputer program products according to various implementations. It willbe understood that one or more blocks of the block diagrams and flowdiagrams, and combinations of blocks in the block diagrams and the flowdiagrams, respectively, can be implemented by computer-executableprogram instructions Likewise, some blocks of the block diagrams andflow diagrams may not necessarily need to be performed in the orderpresented or may not necessarily need to be performed at all, accordingto some implementations.

These computer-executable program instructions may be loaded onto aspecial-purpose computer or other particular machine, a processor, orother programmable data processing apparatus to produce a particularmachine, such that the instructions that execute on the computer,processor, or other programmable data processing apparatus create meansfor implementing one or more functions specified in the flow diagramblock or blocks. These computer program instructions may also be storedin a computer-readable storage media or memory that can direct acomputer or other programmable data processing apparatus to function ina particular manner, such that the instructions stored in thecomputer-readable storage media produce an article of manufactureincluding instruction means that implement one or more functionsspecified in the flow diagram block or blocks. As an example, certainimplementations may provide for a computer program product comprising acomputer-readable storage medium, having a computer-readable programcode or program instructions implemented therein, said computer-readableprogram code adapted to be executed to implement one or more functionsspecified in the flow diagram block or blocks. The computer programinstructions may also be loaded onto a computer or other programmabledata processing apparatus to cause a series of operational elements orsteps to be performed on the computer or other programmable apparatus toproduce a computer-implemented process such that the instructions thatexecute on the computer or other programmable apparatus provide elementsor steps for implementing the functions specified in the flow diagramblock or blocks.

Accordingly, blocks of the block diagrams and flow diagrams supportcombinations of means for performing the specified functions,combinations of elements or steps for performing the specified functionsand program instruction means for performing the specified functions. Itwill also be understood that each block of the block diagrams and flowdiagrams and combinations of blocks in the block diagrams and flowdiagrams can be implemented by special-purpose, hardware-based computersystems that perform the specified functions, elements, steps, orcombinations of special-purpose hardware and computer instructions.

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainimplementations could include, while other implementations do notinclude, certain features, elements, and/or operations. Thus, suchconditional language is not generally intended to imply that features,elements, and/or operations are in any way required for one or moreimplementations or that one or more implementations necessarily includelogic for deciding, with or without user input or prompting, whetherthese features, elements, and/or operations are included or are to beperformed in any particular implementation.

Many modifications and other implementations of the disclosure set forthherein will be apparent having the benefit of the teachings presented inthe foregoing descriptions and the associated drawings. Therefore, it isto be understood that the disclosure is not to be limited to thespecific implementations disclosed and that modifications and otherimplementations are intended to be included within the scope of theappended claims. Although specific terms are employed herein, they areused in a generic and descriptive sense only and not for purposes oflimitation.

1-20. (canceled)
 21. A wireless apparatus configured for high-efficiency(HE) operation, the apparatus comprising: memory; and processingcircuitry configured to: decode a trigger frame, the trigger frameincluding a parameter to indicate resource units allocated for randomaccess, the resource units allocated for uplink data transmission to oneor more HE stations (STAs) including the wireless apparatus; initiate anuplink orthogonal frequency division multiple access (OFDMA)-basedrandom access procedure, in response to receipt of the trigger framethat includes the parameter, to select one of the resource unitsallocated for random access; and generate an uplink data unit fortransmission in the selected resource unit.
 22. The apparatus of claim21 wherein the uplink OFDMA-based random access procedure configures theprocessing circuitry to: initialize an OFDMA Back-off (OBO) counter to arandom value in the range of zero to an OFDM contention window minimumvalue (OCWmin); decrement the OBO counter for each of the resource unitsallocated for random access in the trigger frame; and select one of theresource units allocated for random access when the OBO counter reacheszero.
 23. The apparatus of claim 22 wherein the trigger frame is atrigger frame configured for random access, wherein the trigger frameconfigurable to indicate that the resource units are allocated forrandom access for uplink data transmission by a plurality of HE STAsincluding the wireless apparatus, and wherein when the OBO counter doesnot reach zero after being decremented for each of the resource unitallocated for random access in the trigger frame, the uplink OFDMA-basedrandom access procedure further configures the processing circuitry toresume decrementing the OBO counter in a next trigger frame configuredfor random access.
 24. The apparatus of claim 22 wherein each resourceunit allocated for random access is assigned a predetermined associateidentifier (AID) value in the trigger frame, wherein the parameter toindicate resource units allocated for random access comprises thepredetermined AID value, and wherein the uplink OFDMA-based randomaccess procedure configures the processing circuitry to decrement theOBO counter for each of the resource units assigned to the predeterminedAID value in the trigger frame.
 25. The apparatus of claim 24 whereinthe processing circuitry is configured to randomly select one of theresource units allocated for random access when the OBO counter reacheszero.
 26. The apparatus of claim 24 wherein the processing circuitry isconfigured to select a current resource unit allocated for random accesswhen the OBO counter reaches zero, the current resource unit being oneof the resource units allocated for random access for which the OBOcounter is decremented.
 27. The apparatus of claim 22 wherein the uplinkOFDMA-based random access procedure further configures the processingcircuitry to: obtain a minimum value for the OFDM contention window(OCWmin) from the HE AP; set an initial value for the OCW to the OCWmin;and initialize the OBO counter to a random value in the range of zero tothe OCWmin.
 28. The apparatus of claim 27 wherein the uplink OFDMA-basedrandom access procedure configures the processing circuitry to decrementthe OBO counter by one for every resource unit assigned to thepredetermined AID value in the trigger frame, when the OBO counter isinitialized to a value smaller than a number of resource units assignedto the predetermined AID value in the trigger frame.
 29. The apparatusof claim 28 wherein the uplink OFDMA-based random access procedureconfigures the processing circuitry to decrement the OBO counter by avalue equal to a number of resource units assigned to the predeterminedAID value in the trigger frame, when the OBO counter is initialized to avalue equal to or greater than a number of resource units assigned tothe predetermined AID value in the trigger frame.
 30. The apparatus ofclaim 21 wherein the trigger frame is received from a HE master stationwithin a transmission opportunity (TXOP), and the uplink data unit isgenerated for transmission in the selected resource unit during the TXOPthe TXOP obtained by the HE master station.
 31. The apparatus of claim30 wherein the resource units allocated for random access comprise OFDMAresource units that are arranged within an OFDMA block, wherein theuplink data unit is generated for transmission in the selected resourceunit within the OFDMA block, and wherein the trigger frame furtherincludes an indication of other resources of the OFDMA block assigned toHE stations for scheduled access.
 32. The apparatus of claim 31 furthercomprising transceiver circuitry and one or more antennas to receive thetrigger frame and to transmit the uplink data unit in the selectedresource unit.
 33. A non-transitory computer-readable storage mediumthat stores instructions for execution by processing circuitry of awireless apparatus to configure the apparatus to perform operations to:decode a trigger frame, the trigger frame including a parameter toindicate resource units allocated for random access, the resource unitsallocated for uplink data transmission to one or more HE stations (STAs)including the wireless apparatus, each resource unit allocated forrandom access having a predetermined associate identifier (AID) value inthe trigger frame indicated by the parameter; initiate an uplinkorthogonal frequency division multiple access (OFDMA) based randomaccess procedure, in response to receipt of the trigger frame thatincludes the parameter, to select one of the resource units allocatedfor random access; and generate an uplink data unit for transmission inthe selected resource unit.
 34. The computer-readable storage medium ofclaim 33 wherein the uplink OFDMA-based random access procedureconfigures the processing circuitry to: initialize an OFDMA Back-off(OBO) counter to a random value in the range of zero to an OFDMcontention window minimum value (OCWmin); decrement the OBO counter foreach of the resource units allocated for random access in the triggerframe; and select one of the resource units allocated for random accesswhen the OBO counter reaches zero.
 35. The computer-readable storagemedium of claim 34 wherein the trigger frame is a trigger frameconfigured for random access, wherein the trigger frame configurable toindicate that the resource units are allocated for random access foruplink data transmission by a plurality of HE STAs including thewireless apparatus, and wherein when the OBO counter does not reach zeroafter being decremented for each of the resource unit allocated forrandom access in the trigger frame, the uplink OFDMA-based random accessprocedure further configures the processing circuitry to resumedecrementing the OBO counter in a next trigger frame configured forrandom access.
 36. The computer-readable storage medium of claim 34wherein each resource unit allocated for random access is assigned apredetermined associate identifier (AID) value in the trigger frame,wherein the parameter to indicate resource units allocated for randomaccess comprises the predetermined AID value, and wherein the uplinkOFDMA-based random access procedure configures the processing circuitryto decrement the OBO counter for each of the resource units assigned tothe predetermined AID value in the trigger frame.
 37. Thecomputer-readable storage medium of claim 34 wherein the uplinkOFDMA-based random access procedure further configures the processingcircuitry to: obtain a minimum value for the OFDM contention window(OCWmin) from the HE AP; set an initial value for the OCW to the OCWmin;and initialize the OBO counter to a random value in the range of zero tothe OCWmin.
 38. A wireless apparatus of a master station configured forhigh-efficiency (HE) operation, the apparatus comprising: transceivercircuitry and processing circuitry configured to: configure a triggerframe to include a parameter to indicate resource units allocated forrandom access for uplink data transmission by a plurality of HE stations(STAs), each resource unit allocated for random access having apredetermined associate identifier (AID) value being indicated by theparameter in the trigger frame; transmit the trigger frame within atransmission opportunity (TXOP) obtained by the master station; andreceive uplink data units from the plurality of HE stations within atleast some of the resource units within the TXOP, wherein the uplinkdata units are orthogonal frequency division multiple access (OFDMA)resource units within an OFDMA block, and wherein the HE STAs randomlyselect no more than one of the resource units indicated in the triggerframe.
 39. The apparatus of claim 38 wherein the trigger frame is atrigger frame configured for random access, wherein the trigger frameconfigurable to indicate that the resource units are allocated forrandom access for uplink data transmission by a plurality of HE STAsincluding the wireless apparatus.
 40. The apparatus of claim 39 furthercomprising transceiver circuitry and one or more antennas to transmitthe trigger frame and to receive the uplink data units in the randomlyallocated resource units.